Pocket clinometer



FEB. 21', i950 R. A. KENNEDY ET AL POCKET CLINOMETER Filed July l0, 1948 Fre amm Ew SN3 MN RE AK H .A A

P L GL E0 CR Patented Feb. 21, 1950 UNITED STATES PATENT OFFICE POCKET CLINOMETER Rollis A. Kennedy and Cecil A. Harms,

Seattle, Wash.

Application July 10, 1948, Serial No. 38,008

3 Claims. 1

Our present invention relates to the general art of clinometers, and more particularly to a small, compact clinometer that may most properly be termed a pocket clinometer.

Our present invention contemplates a compactly arranged clinometer of relatively small size so that it may be carried in the pocket of a workman much as he would carry a pocket cigarette lighter, and would be fully enclosed and protected during such periods. When the need arises for its use, the cover is opened and the clinometer may be used as it is by sighting along the sighting means or it may be placed upon a straight edge for a more accurate determination of slope extending over relatively short distances.

It is Well understood that there has been a considerable development of devices intended to measure vertical angles; however, those observed have been of a bulky character and require special cases for carrying them and almost require the experience of a surveyor to make accurate determinations with them. Due to their structure, these instruments are expensive in first cost. In counter-distinction to this form of surveying instrument, we have produced a very compact unit that is intended for very economical manufacture and which, because of its slight bulk, can be carried generally by workmen who have need for the determination of angles in the vertical plane. Construction men have real need for such equipment as this, so that they make quick determinations of grades when they are operating earth-moving machinery particularly, so that they can get very close to the grades required without having surveyors in constant attendance. Transportation men have need for the determination of gradient very frequently, in the transportation of special contracting equipment, and the like, so that they may determine the methods that will have to be employed for moving that equipment. In actual construction work, there is further need for a device that will readily tell if a structural member is level or if it is at a denite batter or gradient, as required. It is to fulfill this need that we have produced our pocket clinometer.

The principal object, therefore, of our present invention is to provide a pocket clinometer that will be a compact, fully protected unit that will read vertical angles in gradient or degrees, or in any other unit that is desired.

A further object of our invention is to provide a pocket clinometer that admits of rugged construction, yet one which may be adjusted so that it can be expected to give very accurate readings.

A further object of our invention is to provide a pocket clinometer which employs gravity as the medium for moving the vertical angle indicating means, and to so mount this movable, gravitycontrolled unit that it will be sensitive to small changes in vertical angles.

Further objects, advantages and capabilities will be apparent from the description and disclosure in the drawings, or may be comprehended or are inherent in the device.

In the drawings:

Fig. 1 is a perspective view showing our device with the cover open and ready for use.

Fig. 2 is a Vertical sectional view taken in a plane normal to the axis of rotation of the gravity controlled unit.

Fig. 3 is a vertical transverse sectional view through our device.

Fig. 4 is a vertical sectional view taken longitudinally of our device, certain upper elements are partially broken away.

Fig. 5 is a diagrammatic View illustrating the manner of using our device.

Referring more particularly to the disclosure in the drawings, the numerals I ll and Il designate respectively the upper and lower housing members of our device. These are hingedly secured together as by hinge l2, and are secured in their closed positions by the resilient latch I4, which engages a suitable protuberance on the housing member l0, as is designated at I5. This may be formed as part of the case, or might be a separate screw or member secured to the case. The lower housing member I0 is box-like in form and should conform generally to the proportions of a full-sized cigarette lighter, to the end that the device itself may be kept small and convenient to carry. The open top of housing member ID is partially covered over by the top plate l1. This plate has a slot which should provide for the movement of the indicator dial and the indicator element itself.

Positioned near the top of housing member I0 and centrally therewith, are the aligned trunnion bushings 2l) and 2l; these bushings are preferably provided with exterior as well as interior threads so that they may be threaded into housing member Ill and come to a snug engagement with the housing due to the exterior flanges provided on ends of the bushings. This construction is probably best shown in Fig. 3. Adjustably positioned within bushings 20 and 2| are the trunnion screws 23 and 24, respectively. Each of the screws 23 and 24 are provided on their exterior ends with means for engagement with a screw driver or wrench so that they may be adjusted easily for end-wise position. The inner ends of screws 23 and 24 are machined to provide the so-called frictionless bearings for the trunnion pin 26 of the gravity-controlled indicator 28. In order that the trunnion screws 23 and 24 may be locked in position once their adjusted position has been attained, we provide the locks nuts 30 and 3l whichiare adapted tobe Vthreaded upon the threaded screws 23and 24.

The gravity-controlled indicator 28 consists essentially of a pointer 34 which is enlarged at its mid-point 36 to provide for the trunnionfZ; the lower portion of indicator 28, as shown in Figs. 2 and 3, is provided with a relativelyz heavy weight 38. Attention is especially invited to this exact structure, as it embodies principles that are-essential to the successful operation of our device -nan1ely, that the trunnion 26 be offsuitable design so that a very minimum of friction will occur at thispoint and secondly, that `weight 38 has an over-abundance of. mass-so `asto make our indicatorsensitive to very small changes in angular displacement.

Coaxiallydisposed with respectlto trunnion 26 i is the graduated dial 4B. Reierenceis made now to Fig. 2 in which it will be noted that the upper exposed segmentoi dial U40 has a mid-point zero, and is thengraduated each side of Zero -in gradience, such as one on'four, one on two,-one onone, two on one, etc.

On the lower or buriedportion of dial -ll it will be noted that the segment is Agraduatedin degrees from a central zero each way. These two graduations have been foundmost generally useful. However, it will be readily apparent, it

is believed, thatany suitable form of graduations may be so employed and particularlyis it desirable-to have two diierent forms of stating the same general relationship, after the showing made in Fig. 2. When so arranged, the userof the equipment need not .be constantly making conversions from oneform of terminology to another; this isy particularly truein so many forms oi construction work where -engineering datais supplied in certain terms, y-et the iworkman in the eld must .use thetermsin which theirtools are graduated, and with which they aremost familiar.

In keeping with our general plan of producing a simple, durable, sturdy device, wend it very desirable to have the slot through which dial 40 and pointerf3fl extend .as close-rlttingas working tolerances will permit, and in order that there be no undue diiliculties in manufacture, it is. de-

sirable to have a removable plate so that hub'AZ may be inserted through the slotAS formed within plate il. We have combined with this requirement a friction-locking device so that the graduated dial 40 may be accurately Zeroed 0r, ii` desired, may be given an artiiicialzero. This often occurs when an operation suoli as, for instance, a ship building ways, is all in a sloping plane, yet references want to. be made 'fromthe normal to that sloping plane. We. achieve this desirable capacity with our device by providing that hub 42 of dial debe a running lit on. the unthreaded portion of the outside of trunnion bushing 2i., so that the dial is free to revolve in any desired position. Then a V-shape'd friction groove 46 is cut in the outer surface oi hubAZ, and adapted to form a locking engagement with this groove is an arcuate friction member43. Friction member 48 is, in turn,.xedly secured toplate 50. It will be understood, it is believed, that by releasing screws 52 and 53, the dial 40 will be unlocked and may be moved about its center of rotation and then re-locked in a new position. Plate 50 also serves to cover a cut-away portion of plate Il so that, in assembly, hub I42 can be passed through the space thus provided. After the graduated dial and indicator 28 are in place, the trunnion bushings arethen screwed into place, followed by 1 the 'proper adjustment of trunnion screws 23 and 24, and finally the indicator is secured in adjusted position by means of lock Anuts 30 and 3|.

vIn using our pocket clinometer for normal usage, we prefer that the proper dial segment is accurately centered. This is achieved by loosenfing lock member 48 and placing the clinometer `on the base that is adjustable and then, by reversal of the clinometers, possibly more than once, the zero point will be accurately determined. Lock member 48 is then secured xedly in position by means of screws 52 and 53.

The usual manner of use will be to apply one of the plane surfaces of case I0 to a structural member or to a straight-edge for temporary use. The clinometerrmay be hand-held and aligned by sighting along one of its edges or by use of the xed sights as 56 and 5l.

It is believed that it will be clearly apparent from the above description and the disclosure in the drawings that the invention comprehends a novel construction of a pocket clinometer.

Having thus disclosed the invention, we claim:

.1. In a pocketclinometer, of the type having an upper housing member and a lowerrhousing member hingedly secured together; a latch adapted to hold said upper housing member in closed engagement with said lower housing member; atop plate for said lower housing member having a slot extending lengthwise thereof; trunnion bushings secured in axial alignment near the upper margin of said lower housing member; trunnion screws adapted to be adjustably positioned within said trunnion bushings; means for locking said trunnion screws in adjustedposition; a trunnion pin axially disposed with respect to said trunnion screws and to be rotatably supported between the same; an indicator xedly secured to -said trunnion pin and adapted to revolve therewith; an upwardly extending indicator pointer and a downwardly extending weight-supporting arm formed as part of said indicator; an indicator weight secured to said weight-supporting arm; and a graduated circular dial, the improvement, comprising: a hub extending outwardly from said diaLadapted for rotary positioning upon one or said trunnion bushings; an annular V friction groove formed on the surface of lsaid dial hub; a friction member mounted on said top plate .with a flange extending downward through said slot, thelower friction edgeo said .ange being concaveand fitting into said V. friction groove, releasing screws running through said'friction member into said top plate providing means whereby the graduated dial may be rotated and xed in a desired position.

2. In a pocket clinometer.- of the type. having an upper housing member; `a lower housingy inember; a latch adapted to hold said upper' housing member in closed engagement with saidlower housing member; ,a vtop `plate .for said lower adjustably positioned within said trunnion bushings; a trunnion pin axially disposed with respect to said trunnion screws and to be rotatably supported between the same; an indicator fixedly secured to said trunnion pin and adapted to revolve therewith; an upwardly extending indicator pointer and a downwardly extending weightsupporting arm formed as part of said indicator; an indicator weight secured to said weight-supporting arm; and a graduated circular dial, the improvement, comprising: a hub extending outwardly from said dial, adapted for rotary positioning upon one of said trunnion bushings; a friction surface formed on said dial hub; a friction member adapted to engage said friction surface; means for adjustably positioning said friction member; and said graduated dial having one-half of its circumference marked in degrees and one-half marked in terms of the ratio between rise and distance for various angles.

3. In a pocket clinometer of the type having an upper-housing member and a lower housing member hingedly secured together; a latch adapted to hold said upper housing member in closed engagement with said lower housing mem ber; a top plate for said lower housing member having a slot extending lengthwise thereof; trunnion bushings secured in axial alignment near the upper margin of said lower housing member; trunnion screws adapted to be adjustably positioned within said trunnion bushings; means for locking said trunnion screws in adjusted position; a trunnion pin axially disposed with respect to said trunnion screws and to be rotatably supported between the same; an indicator xedly secured to said trunnion pin and adapted to revolve therewith; an upwardly extending indicator pointer and a downwardly extending weight- 6 supporting arm formed as part of said indicator; an indicator weight secured to said weight-supporting arm; and a graduated circular dial, the improvement, comprising: a hub extending outwardly from said dial, adapted for rotary positioning upon one of said trunnion bushings; an annular V friction groove formed on the surface of said dial hub; a friction member mounted on said top plate with a flange extending down- Ward through said slot, the lower friction edge of said flange being concave and fitting into said V friction groove, releasing screws running through said friction member into said top plate providing means whereby the graduated dial may be rotated and fixed in a desired position; and said graduated dial having one-half of its circumference marked in degrees and one-half marked in terms of the ratio between rise and distance for various angles.

ROLLIS A. KENNEDY. CECIL A. HARMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATESy PATENTS Number Name Date 496,300 Durand Apr. 25, 1893 592,833 Sanders Nov. 2, 1897 631,793 Hughes Aug. 29, 1899 765,847 Kreatz July 26, 1904 1,054,304 Merkel Feb. 25, 1913 1,155,824 Knittle Oct. 5, 1915 1,287,242 Craig Dec. 10, 1918 1,622,752 Yakesh Mar. 29, 1927 1,844,762 Hilton Feb. 9, 1932 2,022,452 Aegerter Nov. 26, 1935 

